The present invention relates a solid state imaging apparatus which includes a plurality of pixels two-dimensionally arranged in the row direction and the column direction and in which every two of the plurality of pixels that are adjacent to each other in the row direction or the column direction include color filters of different colors, respectively.
In recent years, as an exemplary solid state imaging apparatus, for example, a device shown in FIG. 8 has been known (see Japanese Patent Publication No. 2001-292453).
Hereinafter, the known solid state imaging apparatus described in the above-described publication will be described with reference to FIG. 8.
As shown in FIG. 8, a plurality of pixels are two-dimensionally arranged in the row direction and the column direction. Colors (R, G or B) of color filters in two rows or two columns as a unit appear repeatedly. And sixteen pixels included in an area consisting of four rows and four columns make up. Note that each pixel addition group does not overlap with any other pixel addition group in the row direction and the column direction. In each pixel addition group, the reference numeral 101 denotes a first G using range in which a color filter (G) is used, the reference numeral 102 denotes a B using range in which a color filter (B) is used, the reference numeral 103 denotes an R using range in which a color filter (R) is used, and the reference numeral 104 denotes a second G using range in which a color filter (G) is used.
FIG. 9 illustrates a circuit for adding pixel signals generated in the solid state imaging apparatus of FIG. 8.
First, signals of a pixel 105 and a pixel 106 which are included in the first G using range are stored in a capacitor 107 and a capacitor 108 in FIG. 9, respectively, and then a switch 109 made of an MOS transistor is conducted, so that the signals of the pixel 105 and the pixel 106 are added together and output to an output line 110.
In the known solid state imaging apparatus, the number of capacitors for storing signals is the same number as that of pixels in each pixel addition group. Accordingly, a large number of capacitors are needed.
Therefore, in a solid state imaging apparatus, such as a super mega-pixel apparatus, which is used for a digital still camera, a digital video camera or the like and includes a large number of pixels, a very large number of capacitors are necessary.
For this reason, in a solid state imaging apparatus including a large number of pixels, the configuration of the apparatus is complicated and it is also difficult to reduce the size of the apparatus.